Coronary Artery Bypass Grafting Among Older Adults: Patterns, Outcomes, and Trends

Abstract

Introduction

Although the numbers of older adults in the US are rapidly increasing, there is sparse recent data on the use and outcomes of coronary artery bypass grafting (CABG) among this population. We aimed to evaluate the characteristics and outcomes of older adults undergoing CABG and to measure temporal trends.

Materials and methods

Using data from the National Inpatient Sample (2005-2014), patients aged 85 y and older who underwent CABG were selected. Demographic, clinical, and hospital characteristics were extracted. Outcomes measured were hospital mortality, hospital length of stay, discharge home, and operative complications. Patients were grouped by 2-year increments. Differences in clinical characteristics and outcomes over time were evaluated using trend analyses.

Results

There were 60,124 patients included in the cohort. The mean age was 86.8 y with majority being men (61%), white (88%), and treated in teaching hospitals (61%). Over the study period, the annual surgical volume decreased from 6689 in 2005/06 to 5150 in 2013/14. Mortality decreased from 8.5% to 5.5% (P-trend <0.001) and mean hospital length of stay decreased from 13.9 d to 12.0 d (P-trend <0.001), whereas the rate of discharge home remained stable (14.1% versus 11.6%, P-trend = 0.056). Compared with patients in 2005/06, those in 2013/14 had higher comorbidities [diabetes: 27.6% versus 17.3%; chronic kidney disease: 29.8% versus 9.2%; peripheral artery disease: 7.5% versus 6.0%; and hypertension: 83.7% versus 64.5% (all P-trend <0.001)].

Conclusions

CABG volumes are decreasing among older adults, and comorbidity burden is increasing, but outcomes are improving. These data may indicate improved preoperative optimization and better perioperative care processes.

Introduction

Coronary artery bypass grafting (CABG) is the most frequent cardiac operation performed in the United States accounting for over 200,000 cases annually.^1,2 With improvements in the technique and perioperative care of patients who underwent CABG, criteria for identifying operative candidates and operative outcomes has evolved over the past few decades.^3,4 Operative mortality has decreased from high numbers when it was first introduced to less than 2% in most centers across the United States.^1,5 Adverse events such as cerebrovascular events and need for reoperations are also markedly reduced.¹ Therefore, CABG performed today in well-selected patients is associated with significant survival benefit with acceptable operative risk.

There is a growing population of older individuals in the United States. Between 1970 and 2010, individuals 65 y and older increased from 20 million to 40 million.⁶ While those 85 y and older increased from 1.5 million to 5.5 million.⁶ There are projections that by 2050, more than 20% of the elderly population would be aged 85 y and older.⁶ Despite the increasing number of individuals aged 85 y and older, little is known regarding the use and outcomes of CABG in this population. Studies of CABG patterns and outcomes in the general population may not accurately represent individuals in the oldest age groups of the population due to the marked increases in frailty and comorbid burden in these patients.^7,8 Understanding the patterns and outcomes of CABG in older adults will not only provide estimates that could aid in preoperative decision-making but will create opportunities to identify possible areas for future improvement in the care of this continually growing population.

Therefore, the objective of this study was to make nationally representative estimates regarding the characteristics, outcomes, and temporal trends of CABG among patients in the oldest strata of the population.